Im going to post here a FULL wall of text, that i added in a different UE4 VS CE forum thread in a different forum.
I was the most hyped person you could find for Cryengine, i even found UDK while searching for a leaked version of Cryengine, and it was a MASSIVE dissapointment. Yes, it is pretty, but its completely unusable for anything other than a FPS. Good luck trying to strip all the FPS code from the base, getting a clean state, and even worse, good luck trying to create the game becouse there is no documentation other than some broken things(i have SEVERAL examples) or just useless things. Not a single API explanation, or how Actors work, entities, how to do pathfinding, nothing. I spent more than 20 hours just to try to get a simple “go from point A to point B” using pathfinding from C++. I failed, HARD, in the forums, nobody gave a ****, the only way i could do that is to use the AI system wich is a complete blackbox and did completely wrong stuff i didnt like (like completely stopping and starting again if i changed the path destination). Not to mention, you couldnt extend that AI system until the last engine version, so if you wanted to do ANY kind of AI, you were completely out of luck.
Its scripting is absolutely terrible, a huuuuuge pain. The documentation page about how to expose C++ functions to LUA is broken, the built-in LUA debugger doesnt work, at all. Also, to create a new flowgraph node, again, no proper documentation and even if you reverse engineered the code from the few nodes that you have, its ridiculosuly complicated for what it does.
Also, if you want to add editable variables to the editor, you need to use LUA, and then you go back to the paragraph avobe.
I wasted tens of hours reading its example code, trying to figure out how the hell that engine works, and its code with strange stuff for class architecture, lots of things that are in the “compiled only” part on the engine, without source. And also it has like a comment every 300 lines of code or something like that, so its pretty difficult to follow. And i say this becouse its the worst code reading experience ive seen comparing to reading blender’s source( im not used to C but it makes sense), or OGRE3d source, or Bullet physics code.
In short, there is a reason there is like 2 indie games with Cryengine, and not with a lot of gameplay, games with focus on graphics only. The engine is very very very good for environments, it does pretty cool stuff for the level and its graphics, and so, cryengine has been most used for static, portfolio work than whole games with gameplay. And thats not mentioning the part of the DRM and unability to share a thing unless you discuss a license with Crytek. A little indie, in UDK, just pays that 99$ license and goes to sell stuff. In CE, you couldnt, you needed to license it personally with crytek, and absolutely no details, so if you have your cool game almost made, you want to license, and they say “500K$ with a 20% royalty” you are completely screwed, as you didnt knew the terms until you ask them. Now they seem to have added something to compete against UE4 subscription license. But at least UE4 has it terms public, 20$ monthly +5% royalty. Cryengine doesnt take royalties (apparently), but they also say its only for indies, so, until they give more details and completely remake their whole documentation, i dont even want to try again with that. Not kidding, after a day of messing around with UE4 i was already much more capable of coding stuff than with cryengine after spending more than 50 hours trying to make sense of its code.
TLDR: Hyped for Cryengine, wasted a lot of time with it, screwed due to indie non-friendilness and abysmal documentation.